Oracle教程 2023-02-26

Oracle 视图 V$ASM_FILE 官方解释，作用，如何使用详细说明

本站中文解释

Oracle ASM文件视图是查询ASM存储相关信息的只读视图。它可以用于显示Oracle ASM实例中存在的特定ASM文件和其相关属性的信息。

在Oracle数据库中，可以使用SQL选项 v$asm_file 来查询与 ASM文件有关的信息。此视图具有以下几列：

– 大小：表示ASM文件的大小（以字节为单位）;
– 格式：表示文件的格式，包括磁盘组、相同的条带宽度和控制文件名;
– 文件类型：表示ASM文件的类型;
– 文件名：表示ASM文件的名称;
– 备份文件：表示ASM文件是否已进行了备份;
– 全路径描述符：表示ASM文件的全路径名;
– 文件日期：表示最近更新ASM文件的日期;
– 手册状态：表示ASM文件当前的状态;
– 全局名称：表示ASM文件的全局名称;
– 覆盖状态：表示ASM文件是否被其他文件覆盖;
– 节点编号：表示ASM文件所在的节点编号;
– FILE# ：表示文件的编号。

要使用 v$asm_file 视图，可以使用以下SQL代码段：

SELECT FILE_NAME, FILE_SIZE FROM V$ASM_FILE;

这将列出ASM文件的名称和大小。

官方英文解释

In an Oracle Automatic Storage Management (Oracle ASM) instance, V$ASM_FILE displays one row for each file in each disk group mounted by the Oracle ASM instance.

For example, if there are three disk groups and five files in each, fifteen rows are displayed (unless the query is qualified with a WHERE clause).

Column	Datatype	Description
`GROUP_NUMBER`	`NUMBER`	Number of the disk group containing the file (composite primary key)
`FILE_NUMBER`	`NUMBER`	Number of the file within the disk group (composite primary key)
`COMPOUND_INDEX`	`NUMBER`	A 32-bit number consisting of a disk group number in the high-order 8 bits and a file number in the low-order 24 bits (for efficient access to the view)
`INCARNATION`	`NUMBER`	Incarnation number for the file (composite primary key)
`BLOCK_SIZE`	`NUMBER`	Block size of the file (in bytes)
`BLOCKS`	`NUMBER`	Number of blocks in the file
`BYTES`	`NUMBER`	Number of bytes in the file
`SPACE`	`NUMBER`	Number of bytes allocated to the file
`TYPE`	`VARCHAR2(64)`	Type of the file. Possible values are as follows: `ARCHIVELOG` `AUTOBACKUP` `BACKUPSET` `CHANGETRACKING` `CONTROLFILE` `DATAFILE` `DATAGUARDCONFIG` `DUMPSET` `FLASHBACK` `ONLINELOG` `PARAMETERFILE` `TEMPFILE` `XTRANSPORT`
`REDUNDANCY`	`VARCHAR2(6)`	Redundancy of the file: `HIGH` `MIRROR` `PARITY` `UNPROT`
`STRIPED`	`VARCHAR2(6)`	Indicates how the file is striped: `FINE` `COARSE`
`CREATION_DATE`	`DATE`	Date on which the file was created
`MODIFICATION_DATE`	`DATE`	Date of the last open/close for writing, rounded back to the nearest hour
`REDUNDANCY_LOWERED`	`VARCHAR2(1)`	Indicates whether a file has lower redundancy than what was expected (`Y`) or not (`N`). Redundancy is said to have been lowered for a file when one or more data extents in that file are not mirrored at the level specified by the administrator. In case of unprotected files, data extents could be missing altogether. Another possible value for this column is (`U`), which means that it is unknown. This column is deprecated, and it always displays a value of `U`.
`PERMISSIONS`	`VARCHAR2(16)`	Access permissions of the file, in order of user, group, and other
`USER_NUMBER`	`NUMBER`	User number
`USER_INCARNATION`	`NUMBER`	Incarnation number of the user
`USERGROUP_NUMBER`	`NUMBER`	User group number
`USERGROUP_INCARNATION`	`NUMBER`	Incarnation number of the user group
`PRIMARY_REGION`^Foot 1	`VARCHAR2(4)`	Region used for allocating primary extents: `HOT` `COLD`
`MIRROR_REGION`^Foot 1	`VARCHAR2(4)`	Region for allocating mirrored extents: `HOT` `COLD`
`HOT_READS`^Foot 1	`NUMBER`	This column is not meaningful and its value is always `0`
`HOT_WRITES`^Foot 1	`NUMBER`	This column is not meaningful and its value is always `0`
`HOT_BYTES_READ`^Foot 1	`NUMBER`	This column is not meaningful and its value is always `0`
`HOT_BYTES_WRITTEN`^Foot 1	`NUMBER`	This column is not meaningful and its value is always `0`
`COLD_READS`^Foot 1	`NUMBER`	Number of reads from the file
`COLD_WRITES`^Foot 1	`NUMBER`	Number of writes to the file
`COLD_BYTES_READ`^Foot 1	`NUMBER`	Number of bytes read from the file
`COLD_BYTES_WRITTEN`^Foot 1	`NUMBER`	Number of bytes written to the file
`FILEGROUP_NUMBER`	`NUMBER`	Shows the number of the associated file group
`FILEGROUP_INCARNATION`	`NUMBER`	The incarnation number for the file group the file belongs to in a flex redundancy disk group
`REMIRROR`	`VARCHAR2(1)`	This column has the value `Y` when rebalance is needed for the file after a redundancy change in a flex redundancy disk group, `N` otherwise. A redundancy change can occur when the file is moved to a file group with a different redundancy, or when the redundancy property of the file group is changed. After rebalance is run for the file, the value changes to `N`.
`PARENT_FILNUM`	`NUMBER`	For internal use only.
`PARENT_FILNUMINC`	`NUMBER`	For internal use only.
`CON_ID`	`NUMBER`	The ID of the container to which the data pertains. Possible values include: `0`: This value is used for rows containing data that pertain to the entire CDB. This value is also used for rows in non-CDBs. `1`: This value is used for rows containing data that pertain to only the root n: Where n is the applicable container ID for the rows containing data For this view, the value is always `0`.

^Footnote 1Intelligent Data Placement is desupported starting with Oracle Database 21c. As a result, the PRIMARY_REGION and MIRROR_REGION columns are no longer meaningful. Also, the HOT_READS, HOT_WRITES, HOT_BYTES_READ, and HOT_BYTES_WRITTEN columns are no longer meaningful and always return 0, and the COLD_READS, COLD_WRITES, COLD_BYTES_READ, and COLD_BYTES_WRITTEN columns return statistics for the entire file.

本站中文解释

官方英文解释

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